JPH0216972B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method of compensating for errors in detection outputs of various sensors used for control input of a microcomputer. [Prior Art] Conventionally, in the error compensation method of various sensors such as displacement sensors and position sensors, the amount of error is measured from the standard reference value of the standard output of the sensor using a sensor checker, and based on this amount of error, for example, a shim is The reference output of the sensor was compensated by mechanical compensation means such as pinching the sensor. In addition, as a method of compensation using a microcomputer, in order to compensate for the nonlinearity of the sensor detection output input to the microcomputer, the value to be compensated is entered into the memory of the microcomputer using the keyboard, and the sensor detection output is Technology to compensate for nonlinearity (Japanese Patent Application Laid-Open No. 14999/1983),
Alternatively, in order to compensate for the nonlinearity of the detection output of a temperature sensor, a technique has been proposed in which a constant for compensation is input into the ROM of an arithmetic unit (Japanese Patent Laid-Open No. 137191/1983). [Problems to be solved by the invention] However, when trying to input the compensation values of the sensors to be compensated into the microcomputer using these techniques, it is difficult to input the compensation values for each sensor because the compensation values are different for each sensor. , a different value must be set in the microcomputer for each individual sensor. For this reason, setting errors often occur when setting compensation values, and there has been a need for a method that can easily set compensation values. SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks, and aims to provide a sensor error compensation method that allows setting values for compensating sensor errors to be input simply and with fewer errors. do. [Means for Solving the Problems] The present invention provides a sensor error compensation method for compensating for errors in the detection output of a sensor used for control input of a microcomputer. A check process in which a digital switch that can set a value is installed to measure the error of the standard output of this sensor from the standard reference value to obtain error data, and a compensation process in which the error data obtained in this check process is encoded. The microcomputer includes a recording step of converting it into data and recording it on the surface of this sensor component, and a setting step of literally setting the numerical value of the encoded compensation data recorded in this recording step to the digital switch. is characterized in that the output of the sensor is compensated according to the contents of this digital switch. [Operation] Error data is obtained by measuring the error of the standard output of the sensor from the standard reference value. This error data is converted into coded compensation data while referring to a conversion table, and this coded compensation data is recorded on the surface of the sensor component. The compensation value of the sensor recorded on the surface of the sensor component is literally set in the digital switch of the microcomputer, and the microcomputer compensates the output of the sensor according to the contents of the set digital switch. Therefore, setting errors are less likely to occur when setting the compensation numerical value. [Example] A detailed explanation will be given below based on the drawings of the example. FIG. 1 is a sectional view of the installation of a sensor according to an embodiment of the present invention. In FIG. 1, 1 is a wall of a fuel injection pump of a diesel engine, and 2 is a control rack provided inside the wall. A displacement sensor 3 of this rack 2 is attached to a wall surface 1 through which one end of the control rack 2 passes. In other words, there is a control rack 2 on the wall 1.
A sensor cover 5 that covers the end of the sensor is screwed on. An insulating bobbin 9 around which a primary coil 6 and a secondary coil 7 of a differential transformer are wound is provided inside the sensor cover 5 . A movable core 10 of a differential transformer is connected within the insulating bobbin 9 to the end of the control rack 2 via an insulating rod 11. The insulating bobbin 9 is fixed to the sensor cover 5 with a mounting screw 13 and fastened with a lock nut 14. Lead wires 15 of the primary coil 6 and secondary coil 7 of the differential transformer are inserted through the centers of the mounting screw 13 and lock nut 14. This lead wire 15 is connected to an input interface 18 of a microcomputer 17 for fuel injection timing control shown in FIG. The CPU 19 of this microcomputer 17 has
A digital switch 21 for adjusting the input value of this CPU 19 is connected. Also, the output of CPU19 is
It is guided through the output interface 22 to a hydraulic control valve of a timer (not shown). 23 is a storage device of the microcomputer 17. A method of compensating for errors in the displacement sensor 3 with this configuration will be described. First, before attaching the displacement sensor 3 to the wall surface 1 of the fuel injection pump, the reference output of the displacement sensor 3 is measured via the lead wire 15 with a voltmeter (not shown). Now, the reference output of the displacement sensor 3 is not in an electrically neutral state as shown in the characteristic diagram of FIG.
When the displacement sensor 3 is located at a point, the storage device 2 stores the amount of error from the 0 point, which is the electrical neutral point of the displacement sensor 3.
3 is encoded using the code table shown in Table 1 stored in Table 3.

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Claims (1)

[Claims] 1. A sensor error compensation method for compensating for errors in the detection output of a sensor used as a control input of a microcomputer, wherein a value can be manually set in the input circuit hardware of the microcomputer. A check process is provided in which a digital switch is installed to measure the error of the standard output of this sensor from the standard reference value to obtain error data, and the error data obtained in this check process is converted into coded compensation data to be used with the sensor. It includes a recording step of recording on the surface of the part, and a setting step of literally setting the numerical value of the encoded compensation data recorded in this recording step to the digital switch, and the microcomputer reads the contents of the digital switch. Therefore, a method for compensating errors in a sensor, characterized in that the output of the sensor is compensated.